Gas turbines and their construction are generally known. The rotors of gas turbines may in this case be constructed and assembled in various ways. One rotor variant comprises a multiplicity of elements which lie one against the other and which are braced via a tie rod extending centrally through the elements. These elements are, on the one hand, rotor disks and, on the other hand, tubular sections, what are known as hollow shafts, which may bear against the rotor disks. The rotor disks and hollow shafts are in each case braced by means of screw nuts screwed onto the end faces of the tie rod, the screw nut provided on the compressor side often being designed as a hollow shaft. As a rule, the rotor disks bearing one against the other over a large area on their end faces carry the moving blades of the turbine and of the compressor on their outer circumferences. Instead of one central tie rod, it is also known to use a plurality of decentral eccentric tie rods.
In order to assemble and dismantle a multipart rotor of this type, an assembly tool is known which comprises essentially two bearing blocks. The two bearing blocks are set up at a distance from one another and the rotor is deposited on them. One of the two bearing blocks, what is known as the turning block, is in this case equipped with a joint which is arranged between the foot and the bearing surface and it is fastened to one end of the rotor. The rotor is therefore placed such that its, for example, compressor-side end can be fastened directly to the joint of the turning block. The other bearing block then supports the rotor on the turbine side. The joint fastened to the turning block serves for transferring the rotor out of the horizontal position into a position perpendicular thereto. For this purpose, a suspension nut is screwed onto the tie rod at the turbine-side end of the rotor. A cable of a crane is fastened to the suspension nut by means of a shackle. While the crane is lifting the turbine-side end of the rotor, the compressor-side end rotates about the center of rotation of the joint. The lifting operation is concluded when the rotor has reached an approximately vertical position. It is then secured against tipping over by means of a securing device which is also provided on the turning block. As a rule, this securing device comprises a blocking bolt which is provided, above the joint, on the turning block and which blocks the backward movement of the rotor out of the vertical position. The suspension nut is subsequently demounted, after which the actual work on the vertically set-up rotor (or tie rod) can then be carried out.
To assemble the rotor, first the tie rod is set up vertically, and subsequently the individual rotor disks are slipped onto the tie rod in succession from above by means of a crane. A turbine-side rotor nut is then screwed on. When a fully mounted rotor is being demounted, after it has been set up vertically, the rotor nut arranged on the turbine side is removed, after which the individual rotor disks can be extracted from the tie rod. The rotor then comprises essentially only the tie rod.
A similar setting-up apparatus with a turning block is known from Gelman Laid-open publication 24 26 231. A first stop is fastened centrally, under the turning block, to the foundation. In contrast to the abovementioned apparatus, it is not the end of the rotor which is fastened to the turning block, but, instead, a rotor point at a distance from the end. When the longer rotor section is being lifted, the shorter rotor section then pivots toward the foundation. The coupling flange arranged on the shorter rotor section bears against the first stop after vertical set-up, after which a second stop is then adapted on the other side of the flange and is fixedly connected via screws to the first stop in order to secure the rotor against tipping over.